639 
185 
spy 1 



THE EFFECT OF LARGE APPLICATIONS OF COM 
MERCIAL FERTILIZERS ON CARNATIONS 



BY 



FRED WEAVER MUNCIE 

A. B. Wabash College, 1910 
M. S. University of Illinois, 1913 



THESIS 



Submitted in Partial Fulfilment of the Requirements 
for the Degree of 

DOCTOR OF PHILOSOPHY 
IN CHEMISTRY 



IN 



THE GRADUATE SCHOOL 

OF THE 

UNIVERSITY OF ILLINOIS 



1915 



LIBRARY OF CONGRESS 




002 755 986 4 • 



ACKNOWLEDGMENTS. 
The author desires to express his appreciation of the many helpful sug- 
gestions received from Dr. Geo. D. Beal, Dr. C. G. Derick and other 
members of the departments of Chemistry and Botany. 



THE EFFECT OF LARGE APPLICATIONS OF COM- 
MERCIAL FERTILIZERS ON CARNATIONS 



BY 



FRED WEAVER MUNCIE 

A. B. Wabash College, 1910 
M. S. University of Illinois, 1913 



THESIS 



Submitted in Partial Fulfilment of the Requirements 
for the Degree of 

DOCTOR OF PHILOSOPHY 
IN CHEMISTRY 



IN 



THE GRADUATE SCHOOL 

OF THE 

UNIVERSITY OF ILLINOIS 



1915 



£ IX jQJ* I <\ (G 



Effects of Large Applications of Commercial Fer- 
tilizers on Carnations 

By Fred Weaver Muncie 

In the investigation of the use of commercial fertilizers in growing 
carnations by the Illinois Agricultural Experiment Station, it has been 
found that the lack of appreciation by florists of the relatively high plant 
food concentrations and often high solubilities of commercial fertilizers, 
as compared with manure, has often led to a complete loss of a crop of 
flowers in an effort to produce an extraordinarily large one. On this 
account, it was considered desirable to study the causes and effects of 
overfeeding with the more ordinarily used commercial fertilizers. 

The fertilizers chosen for the experiment were dried blood, sodium 
nitrate and ammonium sulfate, acid phosphate and disodium phosphate, 
and potassium sulfate. For comparison, sodium chloride and sodium 
sulfate also were used on some sections. Experimental work upon the 
subject was carried out during the years 19 12-15. 

Carnations are propagated by means of cuttings, and from these it was 
found impossible to secure a normal growth in either sand or water cultures. 
Hence, the experimental work was based upon the study of plants grown 
in soil carefully selected with the view to securing uniformity throughout 
the benches, watered to give as nearly as possible the same moisture 
" content,' and subjected very nearly to identical conditions of heat, ventila- 
tion, and illumination. For details regarding the type of soil, its prepara- 
tion, arrangement of sections, etc., the reader is referred to Bull. 176 
of the Illinois Agricultural Experiment Station. 



The method consisted of weekly applications of the fertilizers at various 
rates upon isolated sections in the benches, beginning about October i 
and continuing until about May i or until injury became serious. 

Effects of Overfeeding on Condition of Plants. — The rapidity with 
which the sections of carnations became affected followed in a general 
way the solubility of the fertilizer used.* The solubilities** of the pure 
substances in water per hundred parts at o° are given in Table I. 

Table I. — Solubilities of Pure Salts in Water at o°. (Parts per ioo.) 

NaN0 3 (NH 4 ) 2 S0 4 NaCl KC1 K 2 S0 4 

72.9 71.0 35-7 28.5 8.5 

Na 2 HP0 4 .i2H 2 CaH 4 (P0 4 ) 2 .H 2 CaHP0 4 CaS0 4 .2H 2 

6.3 4(15°) °-° 28 °- 2 4i 

Commercial acid phosphate consists of about equal parts of mono-calcium 
phosphate and calcium sulfate. Reversion to monohydrogen phosphate 
in presence of bases in the soil would further decrease the low solubility 
of the acid phosphate and by double decomposition with calcium, iron 
and other bases in the soil render the sodium phosphate first applied less 
soluble, as pointed out by Cameron and Bell. 7 

Dried blood, giving soluble products at a rate depending upon the 
rapidity with which bacterial decomposition proceeds, could not be 
rated as having a known solubility without a study of the bacteriological 
activity of the soil mixture. Tests with litmus paper showed that the 
surface of the soil, neutral at the beginning of the experiment, became 
acid seven or eight days after the addition of the dried blood. Soil to 
which ammonium sulfate was applied became acid as quickly also. 

Single applications of ammonium sulfate and sodium chloride at the 
rate of 12.5 kg. per 100 sq. ft. made on December 3, 19 13, produced marked 
injury within a week's time. Equal amounts of potassium sulfate, at 
this time, followed by further applications at intervals of one or two 
weeks, at the rate of 1.25 kg. per 100 sq. ft., produced no signs of injury 
until about January 15, when a lack of turgidity became noticeable, fol- 
■ lowed by a gradual stunting of growth, with the more pronounced signs 
appearing only after the middle of March. Signs of injury in sections 
treated in the same manner with sodium phosphate became evident even 
more slowly, while acid phosphate produced no apparent injury even in 
the largest applications. 

* The impurities in the ammonium sulfate, potassium sulfate (in this case 1.26% 
of chloride as sodium chloride) and disodium phosphate are not sufficient to interfere 
with the use of the solubilities of the pure substances as a rough measure of the solu- 
bilities of the fertilizers themselves. 

** Van Nostrand — Chemical Annual, 19 10. 



The fertilizers may be grouped into the class, easily soluble and pro- 
ducing almost immediate injury; a second, moderately soluble and pro- 
ducing delayed injury; and a third, difficultly soluble and producing no 
apparent injury. On days of continuous sunlight a more or less pro- 
nounced softness of tissue could be detected by careful observation long 
before characteristic injuries became apparent. 

Effects of Overfeeding with Ammonium Sulfate. — A marked softness 
of tissue was the earliest sign of overfeeding with ammonium sulfate. 
A complete plasmolysis took place in that portion of the stem located 
two and three nodes below the bud and in the portion of the stem just 
above the node, so that the stem bent completely over. The shoots first 
affected were those with buds one-half to three-quarters developed. At 
the same time white spots 0.25 and 1.00 mm. in diameter appeared upon 
the upper leaves of these and the younger shoots. Microscopic examina- 
tion of these showed the chlorophyll bearing tissue entirely plasmolyzed. 

In contrast to the injury from other fertilizers, practically every flower 
split.* This splitting was not caused by the pressing outward of the 
petals as is usually the case, but by a weakening of the tissue at the line 
joining the sepals to form the calyx cup. Later stages resulted in the 
drying up of the leaf tips, and the appearance of the white depressions 
upon the older leaves. The sepal tips very early became brown. Later, 
pustule-like elevations about 1 mm. across appeared on them, caused 
by a crystal of ammonium sulfate beneath the epidermis. The injury 
from excess of ammonium sulfate was more rapid and pronounced in the 
presence of lime than without it. 

Effect of Overfeeding with Sodium Nitrate. — Injury followed heavy 
applications of sodium nitrate within a few days, the characteristic 
symptom being an even lightening of color of the foliage over the plant, 
followed by drying of leaf tips and petals and withering of the plant. 

Effects from Large Applications of Sodium Chloride. **— The first appear- 
ance of injury from large amounts of sodium chloride was two days after 
its application, a plasmolysis of the cells of the stem, causing it to lose its 
rigidity at the crown. When held within supports the plants appeared 
normal. Gradually, however, the plants lost their turgidity and the 
chlorophyll disappeared evenly throughout the entire plant. Tests made 
in the spring of 19 15 with heavy applications of sodium chloride and 
potassium chloride (12 kg. per 100 sq. ft.) showed the same effect from 
each of them, while sodium sulfate, like potassium sulfate, showed less 
injury and that only after a longer period. 

* Splits is a trade term denoting flowers with split calyces. 
** Sodium chloride, while not strictly a fertilizer, was used in the experiments be- 
cause of its presence in considerable amounts in kainite and in some grades of com- 
mercial potassium sulfate. 



Effects of Overfeeding with Potassium Sulfate. — In earlier stages 
partial wilting occurred on days of sunshine. Drying up of the tips of the 
leaves and curling of the leaves upward upon their long axis followed, 
with often, also, a peculiar inhibition of growth on one edge of the leaf, 
with the same on the opposite edge of another portion, giving the leaf a 
wavy outline. 

A marked stunting of growth was observable. This affected most 
noticeably the lengthening of the stem, resulting in the later shoots assum- 
ing a rosette appearance, due to the leaves of normal length upon a stem 
with undeveloped internodes less than an inch in length. (The inter- 
node in full grown shoots is ordinarily three or four inches long.) The 
edges of the petals of the flowers after about the middle of January became 
quite generally withered or crinkled. Those in the center of the flower 
remained closed quite tightly, while the other two or three rows opened 
normally. Later, the buds remained closed, although the pistil often 
pushed its way out and might be seen extending an inch above the top 
of the bud. 

A marked increase in exudation of nectar in the flower was found to 
have caused the gluing together of the petals, and so prevented their 
opening. On cloudy days very frequently a calyx cup would be found 
completely filled with this exudation. The exudation was most plentiful 
in the flowers from plants receiving a moderately heavy application of 
potassium sulfate over a long period of time while the heavier applica- 
tions caused a noticeable but less plentiful increase. A small amount of 
nectar is found in normal flowers, and somewhat larger amounts in the 
flowers from plants receiving large applications of sodium phosphate, 
sodium chloride, ammonium sulfate, or potassium chloride, but not so 
generally nor in such large amounts as in the sections treated with potas- 
sium sulfate. Injury was less marked when ground limestone was added 
to the soil, in contrast to the effect of liming on the production of injury 
by ammonium sulfate. 

Effects of Overfeeding with Sodium Phosphate. — When moderately 
large amounts of sodium phosphate were added over a long period (as in 
19 13-14) no injury was noticeable until about the middle of March, when 
a retardation of growth was evident from the decrease in height of the 
plants and abnormally small buds and flowers. These signs of inhibition 
became steadily more pronounced until the plants were removed from the 
benches, about May first. When larger amounts were used (as 12 kg. 
per 100 sq. ft. in 19 14-15) loss of turgidity in the plants, longitudinal 
rolling of the leaves, death of the leaf tips and softness of the petals of the 
blossom were evident. These signs of injury appeared, however, only 



after the middle of January and then only gradually. Injury was less 
when the soil was limed than when not. 

Effects of Overfeeding with Dried Blood. — In none of the experiments 
with dried blood did injury appear until about the middle of January. 
At that time a softness of the petals and irregularity of their arrangement, 
due to the partial opening of the inner and crinkling of the outer ones, 
became more or less common. The flowers became susceptible to brown- 
ing when a drop of water from syringing lodged on a petal in a position 
to be reached by the rays of the sun. The height of the plants was below 
normal in the spring but rather above in the fall; the color was good. 
If the applications of dried blood were not continued after signs of injury 
became apparent, the plants gradually recovered. The same held true 
for plants overfed with ammonium sulfate in contrast to those which had 
been injured by potassium sulfate, sodium phosphate, and sodium chloride. 

Effects of Overfeeding on the Mineral and Nitrogen Content of Plants. 

— Effects upon the dry weight and ash are shown in Table II, the samples 
being the foliage from the shoots gathered January 9, 1915. 

Table II. — Dry Weight and Ash in Foliage. 



Section 
No. 
269. 


Treatment. 
Check. 


Moist weight. 
G. 
27.6. 


Dry weight. %. 
17.8. 


Ash (sulfated) 

per cent, of dry 

weight. 

13.68. 


271 


125 P* 


324 


17.6 


13-93 


273 


250 P 


32.2 


18.3 


12 


89 


275 


500 P 


30-6 


18.9 


14 


28 


277 


125 K 


26.I 


18.4 


15 


37 


279 


250 K 


36.8 


20.4 


15 


45 


281 


500 K 


32.8 


22 .6 


15 


59 


283 


Check 


28.2 


19.2 


13 


19 


285 


125 NaCl 


42.9 


22.8 


14 


45 



The increase in both values as the applications of any one fertilizer in a 
series were increased is shown in the table. The higher values for plants 
treated with potassium sulfate and sodium chloride over those treated 
with sodium phosphate correspond to the higher osmotic pressure values 
obtained from the sap of these plants as well as to the more rapid injury 
from potassium sulfate. 

Determination of the total nitrogen and mineral content of the ash 
from various samples of plants treated with potassium sulfate gave the 
following values: 

* N, P and K in the tables are used to indicate ammonium sulfate, disodium 
phosphate and potassium sulfate, respectively, while NaCl indicates sodium chloride 
and A. P., commercial acid phosphate. The figures preceding the letters indicate the 
number of grams applied weekly per 20 sq. ft. of bench space. 



Table III. — Effect of Potassium Sulfate. 

Analyses. Per cent. 



Treatment. 


NasO. 


K2O. 


SO3. 


N(total). 


PiOt. 


Check 


1 .09 


5.38 


1 .07 


2.58 


O.72 


K 


1-25 


6.62 


1. 91 


2-53 


O.70 



0.16 1.24 0.84 — 0.05 — 0.02 

The data show an increased sodium,* potassium and sulfur content, 
with practically a constant percentage of nitrogen and phosphorus. 

A similar study of plants to which ammonium sulfate had been ap- 
plied gave the results shown in Table IV. 

Plants to which sodium phosphate was applied showed a higher phos- 
phorus content, 0.60% P2O5 and 1.17% P2O5 in a sample of 19 15 in which 
the calcium content was decreased (2.31 and 1.63% CaO, respectively, 
in the last set of samples) ; the nitrogen content was increased by applica- 
tions of sodium phosphate, the values 1.99%, 2.84% and 3.30% being 
obtained from plants to which had been applied, respectively, none, 
250 g. and 500 g. of sodium phosphate per 20 sq. ft. of bench space per 
week for several weeks. 

Table IV. — Effect of Ammonium Sulfate. 

Analyses. Per cent. 



Treatment. N (total). N(by MgO). SOa. P2O5. 

Check 2 . 05 0.168 0.75 . 93 

N 2.93 0.364 2.10 1 . 14 



0.88 0.196 i-35 0.21 

The ratio 2N/SO3 in ammonium sulfate is 28/80 = 0.351, that of total 
nitrogen to sulfur increase is 0.652; and of nitrogen by MgO 0.145. The 
intake of sulfur when this fertilizer is used is less than is required for the 
nitrogen then, but in excess of that required to be combined with the 
nitrogen determined by MgO.** Limestone was found to depress the 
sulfur intake from ammonium sulfate. Since injury was greater in sec- 
tions so treated, the injury is not proportional to the intake of sulfur. 
The intake of phosphorus was increased by the addition of ammonium 
sulfate, probably due to acidity developed in the soil. 

Table V shows the total nitrogen content of some plants from Sections 
264 (ammonium sulfate and lime) and 281 (ammonium sulfate). Samples 

* Mayer 22 states that the addition of soluble potassium salts to a soil causes a 
partial replacement of the sodium. 

** The author would not care to report the presence of ammonium salts in plants 
not fed with it. It seems, rather, that MgO has caused some decomposition of the 
organic material; the error due to this is assumed to be the same in both samples. 



were collected on April 25, 1914. Section 281 had received but one 
application at the rate of 12.5 kilos per 100 sq. ft. on December 3, 1913, 
while applications at the rate of 1250 g. per 100 sq. ft. were made to Section 
264 at 15 different intervals of about two weeks after December 20, 1913. 
Analyses were made of upper and lower portions of the plant separately 
in order to show any localization of nitrogen in the more vigorously grow- 
ing portion of the plant. 

Table V. — Total Nitrogen Determination on Foliage. 



Section. 


Portion. 


Condition. 


Nitrogen. 


264-E 


upper 


half dead 


4-58 




lower 


half dead 


4.07 


264-P 


upper 


half dead 


7.78 




lower 


half dead 


5 64 


264-P 


upper 


dead 


6. 14 




lower 


dead 


3-41 


264-E 


upper 


alive 


6.69 




lower 


alive 


5 70 


264-E 


upper 


half dead 


7.01 




lower 


half dead 


3-34 


28I-E 


upper 


dead 


4.60 




lower 


dead 


3.02 


281-E 


upper 


partially affected 


4-73 




lower 


partially affected 


3.78 


28I-E 


upper 


half dead 


4-73 




lower 


half dead 


2 94 


281-E 


upper 


slightly affected 


4-47 




lower 


slightly affected 


3-21 



%. 



Sample No. Plant No. 
I I 

2 

3 4 

4 

5 1 

6 

7 11 
8 

9 4 
10 
11 11-15 



13 16 

14 

15 20 

16 

17 7 
18 

The total nitrogen content of the plants varied from once and a half to 
more than twice the normal value found in the previous set. Average 
values for the plants from Section 264 are 6.44% and 4.43%, respectively; 
for those from Section 281; 4.63% and 3.24%. In each case the more 
vigorously growing portion contained the larger percentage of nitrogen 
and the increase over the lower portion is considerably greater in the 
section to which the smaller applications were made during the entire 
season. No clear relation is shown between the nitrogen content and 
the degree of injury. Considerable tolerance for ammonium sulfate is 
shown when it was applied to the soil in quantities not heavy enough to 
produce immediate, serious injury. The fact that the dead plants had no 
higher total nitrogen content than those only injured is evidence that part 
of the nitrogen when added in small quantities was changed to a nontoxic 
form, since the dead plants were in this condition as early as March 21, 
while the living ones though injured undoubtedly continued to take up 
the salt in solution until samples were taken. 

A series of ammonia determinations was made on the sap from "checks" 
and ammonium sulfate fed plants of the set of 1 2-9-14. Folin's micro- 
method for the determination of free 14 ammonia was used, the excess of 



IO 



sulfuric acid (0.01550) being titrated back with potassium hydroxide 
0.02130 with sodium alizarin sulfonate as the indicator. Results are 
given in Table VI. 

Table VI. — Free Ammonia in Plant Saps.* 



Sample No. 


Treatment. 


Appearance. 


Nitrogen. 
Mg. N per cc. 


5 


check 


normal 




none 


8 


250 N 


normal 




0.1834 


7 


500 N 


normal 




1372 


2 


1000 N 


slightly injured 




0.6390 


1 


1000 N 


badly injured 




1 .0560 



The white spots on the leaves of plants treated with ammonium sulfate, 
and of crystals imbedded beneath the epidermis of the sepals were studied 
by microchemical methods. 4 

1. January 21, 19 14. Plant Number 4, Section 281, White Enchantress. 
Plant apparently normal. A drop of sap from the stem of a shoot was 
treated with a drop of ammonia-free hydrochloric acid and chloroplatinic 
acid, and evaporated at room temperature under a loosely covering watch- 
glass. A few crystal masses, tetrahedral and often aggregated in shape 
of a cross, appeared. They were yellow in color. Sap from Number 8, 
somewhat injured, and Number 12, badly affected, gave these characteristic 
crystals, also. 

2. A section of the leaf showing white blotches was immersed in chloro- 
platinic acid after removal of the epidermis and allowed to remain over- 
night. Large and perfect crystals appeared, arranged usually around 
the injured spot, never in it. They were insoluble in 95% alcohol which 
removed the excess of chloroplatinic acid. 

3. A drop of sap from plant Number 4, Section 281 was distilled with a 
pinch of sodium carbonate over a micro-burner and the distillate caught 
in a hanging drop of hydrochloric acid in a cover glass placed on a glass 
ring above it. Treatment as above gave small, yellow tetrahedra in- 
soluble in 95% alcohol. 

Ammonium salts were evidently present and apparently caused plas- 
molysis of certain of the chlorophyll bearing cells. Why injury of this 
type is caused by ammonium sulfate in contrast to the even lightening 
of the color of the whole leaf by the other soluble salts, sodium nitrate 
and sodium chloride, is not known. 

Nitrate determinations according to the phenolsulfonic method of 
Mason 21 were made upon the sap of a "check" and an ammonium sulfate 
fed plant from the set of March 9, 1915. The values of 0.01 and 0.40 
mg. N as nitrate per cc. of sap, respectively, showed that nitrification was 
proceeding in the soil although it was quite strongly acid. 17 

* In earlier stages of feeding with ammonium sulfate, samples have been taken in 
which no NH 3 was detected by this method. 



Total solids and ash were determined on the sap of the set of 1 2-9-14. 
The results, given in Table VII, are calculated to milligrams per cc. of 
sap. 

Table VII. — Total Solids and Ash of Sap. 



Sample No. 


Set date. 


Section. 


Treatment. 


Total solids. 
Mg. per cc. 


Ash.* 
Mg. per cc. 


2 


1 2-9-14 


291 


1000 N 


91.9 




3 




293 


1000 K 


IO4.9 


19.2 


5 




289 


check 


63.8 


II. 8 


6 




261 


check 


62 . I 


12 . I 


7 




265 


250 N 


63.6 


13-9 


8 




267 


500 N 


79-9 


151 


9 




277 


125 K 


643 


16. I 


10 




279 


250 K 


69.9 


17 .2 


11 




281 


500 K 


75-7 


17. I 


12 




283** 


check 


72 . 1 


I50 


1 


I -9-1 5 


269 


check 


84.0 


7-5 


2 




271 


125 P 


81.7 


13.2 


3 




273 


250 P 


86.7 


13-3 


4 




275 


500 P 


93 -o 


15 1 


5 




277 


125 K 


92.3 


13-4 


6 




279 


250 K 


106.3 


20. 1 


7 




281 


500 K 


133-7 


20.0 


8 




283** 


check 


105. 1 


14. 1 



The average total solids content of the sap was 85 . 1 mg. per cc. and the 
ash content 14.9 mg. The influence of the fertilizer applications 
is seen in the increase in both values as the applications of any 
fertilizer were increased in a series of sections. Sample 3 of the first set 
and 6 and 7 of the second, all of which were from plants to which large 
applications of potassium sulfate had been made, showed particularly 
high values.*** The first set of data was obtained by drying the samples 
in a Sargent electric oven at 60-70 °, the second in a vacuum oven heated 
to 50 for 12 hours. The actual value for total solids depended on the 
length of heating but experiments with both sets of data given showed the 
same relative values after several successive heatings. 

* Ash determinations upon the sap were made by careful incineration of the solids 
in 1 cc. of sap in platinum dishes over a low flame to prevent mechanical loss of particles 
of the ash. The low chloride content obviates the danger of volatilization of potassium 
chloride by high temperatures. 

** For some reason total solids and ash determinations always ran higher in sap 
from plants in Section 283 than from those in other "check" sections. The same dis- 
crepancy is seen in the osmotic pressure data for these two sets. 

*** The determination of total solids with accuracy is not possible on account of the 
uncrystallizable solutes in the sap, and on this account the mean molecular- weight 
calculations which often accompany osmotic pressure data were not made. Drying 
on the water bath was found to cause charring of the sap from plants which had been 
treated with ammonium or potassium sulfate. The first showed a higher acidity value, 
the second a higher sugar content. 



12 



Determinations of sodium and potassium in the ash from sap obtained 
on January 9, 19 15, from plants treated with potassium sulfate, were made 
in order to show the increased intake of potassium. Similarly, determina- 
tions of phosphorus were made upon the sap from plants fertilized with 
disodium phosphate. The results ; calculated to milligrams per cc. of 
sap, are given in Table VIII. 

Table VIII. — Mineral Content of Sap. 



Sample No. 


Section. 


Treatment. 


Na 
M 


2O. 


K2O. 
Mg. 


Mg;P 2 07 
Mg 


9 


277 


125 K 


i-4 


9-4 




IO 


279 


250 K 


1 


3 


10 


1 






II 


281 


500 K 


1 


3 


10 


1 






12 


283 


check 


1 


2 


8 


4 






I 


269 


check 










I 


5 


2 


271 


125 P 










6 


1 


3 


273 


250 P 










7 


5 


4 


275 


500 P 










9 


6 



Effect of Overfeeding on Osmotic Pressure of Sap. — Sap was expressed 
from the stems of shoots after freezing them with an ice-salt* mixture, 
and the lowering of the freezing point determined by the method of Harris 
and Gortner** of allowing supercooling until the solution froze and cor- 
recting the value of A' obtained by the formula 

A = A' — 0.0125 wA' 
where A' is the maximum temperature attained in the system and u the 
difference between this value and the minimum temperature. The 
relation between A and the osmotic pressure given by Lewis 19 in the 
approximate equation 

■k = 12.06 A 
was used in calculating the value for ir. 

Description of Experimental Method. — Choosing a time when for two 
or more hours previous no appreciable draft had been stirring the air in 
the greenhouse, from four to eight shoots at the same stage of growth 
were removed from each of the sections of plants and quickly taken to 

* Care was taken to select samples from the check and affected plants at the same 
time of day and shoots in the same stage of growth were taken, to insure freedom from 
variations in osmotic pressure due to differences in location and illumination, while 
the fact that the sections studied were usually adjacent obviated the difficulty that 
differences in temperature change the osmotic pressure of plants. See Dixon and 
Atkins, 11 Atkins, 3 Ewart, 13 Drabble and Drabble, 12 Cavara. 8 

** The method in genera! was an adaptation of that recommended by Gortner 
and Harris. 15 " 18 Andre 1 and also Dixon and Atkins 11 have shown that successive por- 
tions of sap expressed from unfrozen tissue become more concentrated, while the latter 
have shown that the sap from frozen tissue always has a lower freezing point than that 
from unfrozen, and that successive portions gave nearly identical lowerings, leading 
to the conclusion that sap so expressed is representative of that originally within the 
tissue. 



13 

the laboratory. After removal of the foliage from the stems, they were 
broken at the nodes and placed in hard glass test tubes (25 mm. X 150 
mm.), stoppered with rubber stoppers and sealed with oil paper and rub- 
ber bands. Freezing was produced by the use of the ice and salt bath,* 
giving a temperature of — 15 ° or lower and allowing the tubes to remain 
in the refrigerator overnight. The tubes were then removed from the bath 
and after the walls had been cleaned with distilled water and wiped dry, 
the portions of shoots were removed, thawed gradually, and the sap ex- 
pressed by pressure from the screw of a tincture press set perpendicular 
to the wall upon two pieces of 3 / 8 inch plate glass. After a first expression, 
the shoots were rearranged and pressure again applied. The sap was 
filtered through an S. & S. 589 filter — with a watch glass over the funnel 
to minimize evaporation — into a small test tube; a drop of xylene was 
added as a preservative and the tubes placed at once in a refrigerator, at 
about io°. The sap after filtration was usually a clear, brown liquid 
without sediment. 

As soon as convenient the freezing-point determinations were made. 
A thermometer was used having a bulb about 5 mm. by 35 mm., the mer- 
cury tube enclosed in a hollow jacket, and graduated to — 6.5 in tenths 
of degrees, upon which, by the aid of a lens, hundredths of a degree could 
be read without danger from parallax. A stirrer of platinum wire and 
the thermometer were placed in the 5 cc. of sap contained in a test tube 
of Bohemian glass (15 X 120 mm.) and the whole cooled to about +2 
in an ice and salt bath in a beaker. The tube was wiped free from water 
and placed within a hard glass test tube (25 mm. X 150 mm.) set two- 
thirds way into the ice and salt-freezing mixture. It was found saving 
of time to place this bath in a Dewar bulb, with inside diameter of 35 X 
130 mm.; the top was closed with a piece of cork; the bath so arranged 
remaining effective for three hours or more of use. During the entire 
cooling, the sap was constantly stirred to prevent its freezing about the 
sides of the tube. The lowest temperature obtained was read to one- 
tenth, and the maximum, by the aid of a lens, to one-hundredth degree. 
The tube was removed to a beaker of water, and after the temperature 
had risen to about io°, the determination duplicated to within 0.01 , 
usually without difficulty on the first trial. A typical determination 
gave the following values: 

A' = 1.28 u = 4.12 A = 1. 214 

A' = 1.27 u = 3.43 A = 1. 216 

Average 1.2 15 from which w = 14.64 atmospheres. 

* It was found convenient in case less than a dozen tubes of material were frozen* 

to place the ice and salt bath in one or two one-liter Jena beakers. In this way the 

ice can be packed about the upper portions of the test tubes, and the beakers, with five 

or six test tubes in them, are narrow enough to keep the tops of the test tubes from 

touching the solution. 



H 



Osmotic Pressure Determinations. 

Treatment. 
IOOO N 

iooo K 

IOOO P 

check 
check 
iooo N 
iooo K 
iooo P 
check 
check 
check 
iooo N 
iooo N 
iooo K 
check 
check 

250 N 

500 N 

125 K 

250 K 

500 K 
check 
check 

125 P 

250 P 

500 P 

125 K 

250 K 

500 K 
check 

125 NaCl 

500 A. P. 

Discussion of Results. — No comparison can be made between the 
values for the osmotic pressure determined in successive sets on account 
of variations due to temperature, physiological scarcity of water, etc., 
but the values obtained from plants in adjacent sections at the one time 
are regular enough to be comparable. 

From the values for osmotic pressure of Samples 7, 8, 2 and 1 of the set 
of 1 2-9-14 the conclusion was drawn that the osmotic pressure within 
the plants increased as the quantity of ammonium sulfate applied to the 
soil was increased. Samples 2, 3 and 4, and 5, 6 and 7 of the set of 1-9-15 
gave similar results with increasing applications of sodium phosphate 
and potassium sulfate. The values obtained from the application of 
sodium phosphate were in every case lower than those obtained from appli- 
cation of equal quantities of potassium sulfate or ammonium sulfate. The 





Table 


IX — 




Sample 




Date. 


No. 


Section 


II-I2-I5 


I 


291 




2 


293 




3 


295 




4 


289 




5 


269 


II-20-14 


1 


291 




2 


293 




3 


295 




4 


289 




5 


283 




7 


283 


I 2-9-I 4 


1 


291 


(iO A.M.) 


2 


291 




3 


293 




5 


289 




6 


261 




7 


265 




8 


267 


12-9-14 


9 


277 


(4 P.M.) 


10 


279 




11 


281 




12 


283 


I-9-I5 


1 


269 




2 


271 




3 


273 




4 


275 




5 


277 




6 


279 




7 


281 




8 


283 




9 


285 




10 


287 



A'. 


u. 


A. 


7T. 


I.30 


3-21 


1 .2IO 


I4.6O 


1-37 


403 


I .261 


15-21 


1.32 


5i8 


I.I9S 


14.41 


1. IS 


3 90 


I 054 


12 .71 


1 .00 


1 . 10 


O.946 


II. 41 


1-33 


567 


I . 196 


I4.42 


1.50 


3 40 


I.396 


I6.84 


1 . 10 


4.80 


O.994 


11.99 


1 .20 


5-8o 


I.078 


I3.00 


1. 18 


2.87 


I .098 


13-24 


1.27 


4-43 


I . 160 


13-99 


1.66 


5-34 


I.SI3 


18.24 


i-43 


4.78 


I-305 


15-73 


1 .40 


5 30 


I .267 


15-25 


o.95 


4-55 


O.856 


10.34 


0.99 


3-91 


O.9OI 


IO.86 


1 . 10 


510 


O.990 


11.94 


1.28 


5-4° 


I. 174 


14. 16 


1.05 


3-75 


O.962 


11 .60 


1. 18 


4.82 


0.973 


"•73 


1. 18 


4-32 


I .076 


13.01 


1.06 


4.14 


O.967 


11.68 


1 .20 


4.00 


I . IOO 


13-24 


1.28 


4.62 


I . 169 


14.08 


1.32 


4.98 


I. 178 


14.20 


i-39 


3-8i 


I.284 


I5-50 


i-35 


2.65 


I.265 


15-29 


1.58 


4.92 


I.448 


17-49 


1.87 


4- 6 3 


I .722 


20.76 


1.28 


4.92 


I . 161 


14.04 


1.88 


2 .92 


I. 771 


21 .40 


1.48 


5-52 


1.338 


16. 13 



15 



samples taken on ,r.M, and IMM4 gave higher values for the sap 
from plants overfed with potassium sulfate than those treated with am- 
monium sulfate, but later in the year in the set of 12-9-14 (Samples ■ 
and 2) the relative values are reversed. 

In the set of 12-9-14 P^nts treated with potassium sulfate at the rate 
of .000 g. per section per application were still apparently normal ^al- 
though the osmotic pressure amounted to 15.25 atmospheres, while plants 
treated with one-half this weight of ammonium sulfate possessed an os- 
motic pressure of only 14.. 6 atmospheres and showed signs of injury. 
Injury on the other hand, had not appeared on plants treated with am- 
monium sulfate (250 g. per section per application) when the osmotic 
pressure amounted to 12.42 atmospheres as compared to ... 34 atmos- 
pheres in the adjacent "check" section (.2-9-14-10 a.m.). 

The higher value of Sample . over Sample 2 (of the set of 1 2-9-1 4- 
IO A.M.) was correlated with a greater degree of injury by the am— 
sulfate Injury appeared on the plants from sections to which potassium 
u ate was ippiied'only when an osmotic pressure of over twenty ^a mos- 
pheres was reached (1-9-15). and an osmotic pressure value up to .5.50 
Atmospheres was found in plants on soil treated with sodium phosphate, 
St injury being apparent. The determination of the vakie on h 
sap from plants treated with acid phosphate gave .6. 11 atmospheres, 
"et iTe plants exceeded in size and vigor those to which no fert ize^ 
was applied (.-9-15). The conclusion to be drawn from these facts 
"thi wuh a single fertilizer, injury from overfeeding becomes apparent 
when a certain osmotic pressure is reached, but that this value ,s different 

"injury ' implications of sodium chloride at the rate of .25 g. 
per section per application, occurred at approximately the same tune, 
wis very similar to and was of about the same -e^e - ^t from ap- 
plications of potassium sulfate, in four times these quantities. The rela 
tWe osmotic pressure values are given in Samples 9 and .0 Uysh 
The solubilities of these salts, as pointed out on page 2785, at o are 
™a « c rp^nectivelv giving a ratio roughly oi 4 to 1. 

^Effects of 6 erf ed ng on the Total Acidity of the Cell Sap-Reaction 
Effec s overie g ^ ^.^ nQ fertlhzer 

luv rnuretaT nS or slightly alkaline in the fall, and th. a gradua 
chanre to slight acidity took place durmg the winter. Commercial 
acid phosphate dried blood and ammonium sulfate upon the sod each 

ncrlatd thftotal acidity,* the first one immediately after application, 

increased by addition of comrn "<fj^r^ ™ oviding a sligh t excess of tri- 

zszssr =?*lS:t?S hsr — 1H! = M x 

IO -* for the di-hydrogen sodium phosphate at 18 in 0.1 JS 



i6 



the latter two within about a week's time. In the case of these fertilizers, 
the surface of the soil became acid after the lower portions. When di- 
sodium phosphate was applied, the surface of the soil became alkaline 
to litmus, the deeper parts becoming alkaline more slowly. Tests on 
Section 275 (500 P) on February 18, 19 15, and on 291 (1000 P) on March 
22, 19 1 5, showed that the soil at each successive inch to the bottom of the 
bench, was alkaline to litmus. In so far as could be determined by this 
method, applications of potassium sulfate and of sodium chloride did not 
change the reaction of the soil.* Hence an opportunity was given to study 
the effect, upon the acidity of the cell sap, of fertilizers producing increased 
acidity in the soil, alkalinity, and no change in reaction, and upon the re- 
lation the changes bore to injury from overfeeding with the fertilizer. 

Determinations were made by titrating at about 15 ° with C0 2 -free 
KOH, approximately 0.02 N, 1 cc. portions of sap diluted to 6 cc. with 
CCVfree water, using phenolphthalein as the indicator. Results are cal- 
culated as cc. of normal acid per cc. sap.** 







Table X — 


-Acidity of Plant 


Sap.*** 




Date. 


Samp 
No. 


le 

Section. 


Treatment. 


Condition 
of plants. 


Cc. N acid. 


12-IO-14 


I 


291 


IOOO N 


affected 


O . 03068 




2 


293 


1000 K 


normal 


O.02492 




3 


295 


IOOO P 


normal 


O.05490 




4 


289 


check 


normal 


O . 02048 




5 


261 


check 


normal 


O.02090 




6 


265 


250 N 


normal 


O.O2238 




7 


267 


500 N 


affected 


O.02728 




8 


277 


125 K 


normal 


O.02088 




9 


279 


250 K 


normal 


O . 02002 




10 


281 


500 K 


normal 


O.0213O 




11 


283 


check 


normal 


O.02130 


I-I4-15 


12 


269 


check 


normal 


O.O1977 




13 


271 


125 P 


normal 


O . 05035 




14 


273 


250 P 


normal 


O.06438 




15 


275 


500 P 


normal 


O.O7415 




16 


277 


125 K 


normal 


O.02319 




17 


279 


250 K 


normal 


O.02039 




18 


281 


500 K 


affected 


O.02422 




19 


283 


check 


normal 


O.02252 




20 


285 


125 NaCl 


affected 


O.O187O 




21 


287 


500 A. P. 


vigorous 


O.06981 



* See, however, Maschaupt. 20 
** For memoir on acidity in plants, see Astruc. 2 
*** Boiling a solution of C0 2 in distilled water under diminished pressure by warm- 
ing the test tube with the hand was found completely to remove the C0 2 . Similar treat- 
ment of sap gave identical values for acidity before and after. Hence, the acidity 
was not due to dissolved CO2. 



17 

Acidity values remained about the same when potassium sulfate was 
applied, but increased after applications of acid phosphate, ammonium 
sulfate or disodium phosphate, being proportional in each case to the 
amount put on the soil. The increased total acidity following applications of 
disodium phosphate (which is alkaline to phenolphthalein) was unexpected 
and a more detailed study was made of the sap from these plants. Ether- 
soluble acids were absent and none of the phosphate was extracted by 
moisture-free ether. Phosphate was determined in i cc. portions of 
Samples 12-15 an d the total acidity of the solution calculated on the as- 
sumption of the phosphorus being present (1) as orthophosphoric acid, 
and (2) mono-alkali phosphate,* the values being given in Table XI. 





TABLE XL- 


-Acidity of 


Sap 


by Titration 


and Calculation. 


Sample 
No. 


Treatment. 


Mg 2 P207. 






Acidity. 




As H3PO4. 


As XH2PO4. 


By titration. 


12 


check 


0.0015 




0.02692 


O.OI346 


O.O1977 


13 


125 P 


0.0061 




0. 10768 


O.05384 


O.05035 


14 


250 P 


00075 




. 1 3460 


O.06730 


O . 06438 


15 


500 P 


. 0096 




0. 16348 


O.08174 


O.07415 



The values calculated as XH 2 P0 4 agree more closely than those for 
H3PO4, pointing to the presence of the phosphate as mono-alkali phos- 
phates. Subtraction of the "check" value for Mg 2 P20 7 from each 
of the other values to obtain the increase in phosphate intake due to 
applications of disodium phosphate and comparison of the titratable 
acidity calculated from these results with the excess of acidity of the solu- 
tions over that of the "check" gives the following results: 

Table XII. — Acidity and Phosphorus Content Due to Overfeeding. 

Increase in P2O5. 



(1) As MgaPaOv. 


(?) As MgmH. 


Titration. 
(3) As MgmH. 


Ratio. 
(3)/(2). 


O . OO46 


O.O3999 


O . 03058 


O.765 


O . 0060 


O.O5388 


O . 0446 1 


O.827 


O . 008 1 


O.07276 


O.O5438 


0747 



The ratio between the value of H determined by titration and by the 
gravimetric method at 15 ° was determined to be 0.905, so that the ratios 
obtained are in the same direction, although the lower values for the sap 
indicate that some of the phosphate may have been present as the mono- 
hydrogen phosphate. 

This method was applied to the problem of determining the salt in form of which 
phosphorus enters the plants. In every case increasing applications of disodium phos- 
phate gave higher acidity values. When brown rock phosphate was used (nasturtiums 
grown in sand culture with Hopkin's nutrient solution omitting phosphorus after the 
first application) a regular increase up to a maximum in size of plants followed by a 

* Two hydrogens of orthophosphoric acid and one of monosodium phosphate 
when the solution is concentrated at o° and phenolphthalein is the indicator. 26 At 
higher temperatures, hydrolysis of the salt increases the alkalinity of the solution. 



i8 

decrease was obtained, without a consistent variation in the acidity of the sap. Rock 
phosphate apparently is not taken into the plant as mono-calcium phosphate. 

Reaction of the soil to litmus paper was determined from time to time. 
After the first applications of sodium phosphate the soil reacted alkaline 
to litmus on the surface, with decreasing alkalinity or acidity as the dis- 
tance below the surface increased. On March 22, 1915, Section 295 
(to which applications of 1000 g. of sodium phosphate had been made) 
was found to have an alkaline reaction to litmus paper when tested for 
each inch of soil down to the bottom of the bench (5 inches). Two 
shoots each from plant Number 4, badly injured, and plant Number 12, 
apparently normal, were taken and the sap expressed without previous 
freezing. The sap reacted acid to phenolphthalein in each case. 

The power of soils to absorb bases from salts is well known. 6 With 
this in mind, a liter of solution of disodium phosphate was made up with 
carbon dioxide-free water, and aliquot portions titrated with standard 
sulfuric acid to a faint rose coloration, using phenolphthalein as the indi- 
cator. Six carnation cuttings, rooted in water, were cleansed by repeated 
washing with distilled water and floated on the surface of 500 cc. of the 
solution by placing them in holes of a paraffined cork. They were placed 
in the greenhouse for six days, covered with a large bell jar and shaded 
during the daytime. The cuttings were taken out, the solution care- 
fully rinsed off and after removal of the roots the remainder of the shoots 
was frozen, the sap expressed, and 1 cc. portions titrated with standard 
alkali, using phenolphthalein as the indicator. Comparison was made 
with the acidity of the sap from cuttings taken from the cutting bench 
and prepared as in the former case for sap expression. 

Strength ok Solution 2 G. Na 2 HP0 4 .i2H 2 per Liter. 

Titration of 10 cc. portions Titration of plant sap. 

H2SO4 (0.01550 N). KOH (0.02130 N). 



(1). (2). (1) Check. (2) Treated. 

0.32 cc. 0.31 cc. 0.92 cc. 1. 3 1 cc. 

0.0048 cc. N alkali per cc. 

In the absence of soil, the sap had become more acid when the plants 
were grown in the disodium phosphate solution, hence the increased 
acidity could not be attributed, at least entirely, to the absorptive power 
of the soil for bases. 

Effect of Large Applications of Potassium Sulfate on Carbohydrate 
Content of Sap and Foliage. — The increased exudation of nectar and 
gluing together of the petals in the flowers on plants which had been treated 
with large amounts of potassium sulfate has been listed among the charac- 
teristic signs of overfeeding with this fertilizer (page 6). An attempt 
was made to determine the cause of this increased flow. 

The amount of nectar present in an affected flower amounted to as much 
as i cc. in the spring of 19 12-13, when applications of potassium sulfate. 



19 

moderate when compared with those used in 19 14-15. were made weekly 
during the season October to May. In 19 14-15 the flow was not so plenti- 
ful, although noticeably greater than in the "check" flowers. In the for- 
mer year, the nectar was a brownish liquid with a sweet and bitter taste, 
miscible with water, while in the latter year it was a clear, colorless 
liquid. It had a sweet taste, and was neutral to litmus and phenolphthal- 
ein. It charred on ignition on a platinum foil, with the odor of burnt 
sugar, leaving a small amount of ash which was alkaline to moist litmus 
paper and to phenolphthalein. Sodium and potassium flame tests were 
positive, calcium doubtful . No indication of tannin was given by tests with 
neutral ferric chloride and with potassium ferricyanide and ammonia. 
A solution made by washing off the nectar with distilled water reduced 
Fehling's solution. A heavy osazone precipitate of bright yellow color 
was thrown down upon heating it in a boiling water bath with phenyl- 
hydrazine, acetic acid and a crystal of sodium acetate, after three minutes' 
boiling. Ten minutes' boiling increased the amount. A much heavier 
osazone precipitate was given after a few minutes' boiling with hydro- 
chloric acid, and a portion of the solution inverted by the Clerget method 
gave a heavier osazone precipitate than a similar amount before inver- 
sion. The rotation in a 1 dm. tube of 1 . 5 ° Ventzke was changed to 1 . 18 ° 
V. after the Clerget inversion. Hence, glucose and sucrose were present. 
The precipitate formed in the hot solution was filtered off and the filtrate 
again boiled till no further precipitate separated. On cooling the fil- 
trate a further precipitate of sodium acetate and osazone separated. 
This osazone possessed a roset structure characteristic of maltosazone, 
and was soluble in the boiling solution and reprecipitated from it on 
cooling as is maltosazone. Not enough of the precipitate could be ob- 
tained after recrystallization for a melting-point determination.* Tests** 
made with a guaiacol solution and neutral hydrogen peroxide gave a nega- 
tive test with the exudation, but an equally intensive color with sections 
of petal, ovary, leaf and stem of both normal and affected plants. Neither 
of the reagents used alone gave a reaction. Microscopic examination of 
the lower, plasmolyzed portions of the petals showed the cell walls intact 
and of normal thickness. It was concluded from this that the increased 
amount of sugar was not due to breaking down of these cell walls, but was 
an exudation. Experiments were then undertaken to compare the sugar 
content of the sap expressed from the stems of the plants not fertilized and 
of those receiving applications of potassium sulfate. Evidence that a 
larger amount of sugars was present in the sap of the latter plants was 
* Brown and Morris 5 used 200 g. of leaf tissue in order to obtain enough for prep- 
aration of maltosazone. 

'** Griiss 16 believed gummosis might be caused by an excess of diastatic enzyme 
and used this reagent as a means of detecting it. 



found during the determination of total solids of the sap (vide supra), 
when the residue from this sap was of greater weight and charred at a 
lower temperature than that of the cheek. 

The comparative optical rotations* and copper-reducing powers of 
sap from "check" sections and those which had received applications of 
potassium sulfate are shown in Table XV. 

Table XV. — Optical Rotation and Cu-Reducing Power of Sap Solutions. 



Rotation 
circ. degrees 



Reducing power. 
Ms. CuO. 



Date. 
1-9-15° 



2-IO-15 



2-17-15 



3-9-15 



Treatment, 
check 
125 K 
250 K 
500 K 
check 
K 
check 
250-500 K 
check 
250-500 K 



Orig. 

0.73 
I. 91 

I.42 
I.49 

3 -23 
3-5i 
2.81 
3.26 

2-43 
3.00 



Hydrolyzed. 
O.83 
I 25 
O.97 
I .21 
I .20^ 

i-35 

i-53 
2.28 

i-43 
1 .91 



Complete. * Orig. 



Clerget. Complete 



556 
476.5 

521 
522 



1434 
1 46 1 

1276 

1273 



1654 
1976 

(1282) 
H38 



In view of the work of Davis, Daish and Sawyer, 9 it seems possible, 
though not proven, that the quantitative relationships of the sugars 
in expressed sap may not represent the condition within the living tissue. 
The consistently higher values obtained by both methods of estimation, 
showed, however, that the application of potash to the soil had resulted 
in an increased carbohydrate production, in a more rapid hydrolysis of 
starch, or in a greater permeability of the cell membranes in the meso- 
phyll tissue, so that a larger amount of sugar was found within the conduc- 
ing and storage tissues. 

Leaf tissue (Set 2-10-15) dried at 50-70 ° was extracted with 80% 
alcohol (1 g. pptd. CaC03 being added to neutralize acids present) and 
the extracts, after removal of alcohol, cleared with 5 cc. neutral lead ace- 
tate, 1 cc. basic lead acetate and alumina cream. The extracts from 7 g 

* A. Schmidt and Hausch half-shadow polariscope, with tubes 4 dm. long, was 
used. CuO values were obtained by using Defren's 10 solution, the copper being de- 
termined by Low's method (Treadwell and Hall, p. 682). 

5 cc. sap diluted to 50 cc. cleared with 5 cc. basic lead acetate (sp. gr. 1.115) 
and an excess of alumina cream. 

6 20 cc. sap diluted to 100 cc. cleared with 10 cc. basic lead acetate and alumina 
cream. 

c 10 cc. sap diluted to 100 cc. with 5 cc. basic lead acetate and alumina cream. 
10 cc. sap diluted to 100 cc. with 2 cc. basic lead acetate and alumina cream. 

e Hydrolyzed 24 hours with 10% 0.5 N HC1 at 70 °. 

{ Clerget inversion. 

" Inversion for 3 hours in boiling water bath of 25 cc. soln. 12V2 cc. water and 
2.5 cc. HC1 sp. gr. 1. 19. 



21 



made up to ioo cc. gave values shown in Table XVI. A trace only of 
pentoses was found in the extract. 

Table XVI. — Sugar Determinations in Extracts. 



Cupric-reducing power. 
Mg. CuO. 



Section. 


Treatmen 


268-270 


check 


277 


125 K 



Original. Clerget. Complete. 

3980 1656.8 1933 .6 

652.8 1873.6 I990.4 

The results are similar to those in Table XV. 

Examination was made for starch in carnation leaves taken from the 
plant after a day of sunshine by boiling them for some time in alcohol, 
then in water, and testing leaf sections with an alcoholic solution of iodine ; 
starch was found to be plentiful. Comparative determinations of the 
starch content* were made upon the residues from sugar extractions, using 
a diastase solution prepared by extraction of ground malt with mono- 
sodium phosphate solution at ice-box temperature, but not dialyzed.** 
Fifty cubic centimeters of water were added to the residue and the starch 
gelatinized by boiling for five minutes, with continuous stirring. After 
cooling to" 60 °, 5 cc. of the diastase solution were added with a pipet and 
digestion allowed to proceed for an hour. The mixture was again heated 
to boiling and 5 cc. of diastase again added and after an hour the mixture 
was filtered and washed thoroughly. The maltose in the filtrate was 
hydrolyzed to glucose by the modified Sachsse method and glucose deter- 
mined with Fehling's solution, correction being made for maltose in the 
diastase solution. The values obtained for samples from sets of 2-10-15 
and 2- 1 7- 1 5 are shown in Table XVII. 

Table XVII. — Starch Content of Carnation Leaves. 

Starch per cent. 

Treatment. 2-10-15. 2-17-15. 

check 2.72 3 . 44 

K 1.94 3 09 

A lower starch content in "check" tissue is indicated by the results. 
While these analyses were not made over a long enough period to form 
a basis for a conception of the effect produced by potash upon carbohydrate 
production and transformations, the higher sugar with lower starch 
content is interesting in view of the work of Sherman and Thomas 24 upon 
the activating action of potassium sulfate upon diastase. 

Summary. 
The purpose of the investigation was to determine the effects upon the 
plants of large applications of certain commercial fertilizers to the soil 
on which carnations were grown. 

* Brown and Morris 5 state that preliminary washing with cold water as in the 
O'Sullivan method, is unnecessary in Tropaeolum majus. 

** Sherman and Schlesinger, /. Am. Chem. Soc, 25, 1619 (1913)- 



22 

The injuries characteristic of an excess of each fertilizer are recorded 
from observations made in the greenhouse. 

Determinations of dry weight and ash made upon the foliage of the 
plants, showed an increase in both values with increased applications of 
the fertilizers. 

A sufficient number of determinations of the mineral constituents of 
the foliage was made to show the increased content of the fertilizing salts 
in the plants after large applications of them to the soil. 

Total nitrogen determinations made upon plants in different stages of 
injury showed an increased intake of nitrogen when ammonium sulfate 
was applied but an acquired tolerance by the plant when successive small 
applications were made. Injury from ammonium sulfate is not propor- 
tional to the total nitrogen content. 

The sap was expressed from the stems of the plants after freezing to 
render the plasma membrane permeable to the contents of the cells. 
Osmotic pressure determinations made upon this sap proved that with each 
fertilizer used the degree of injury varied with the osmotic pressure, 
but that not the same degree of injury was caused by different" fertilizers 
at the same osmotic pressure. Injury is not a result of increased osmotic 
pressure exclusively. 

The increase in the osmotic pressure in a series of plants on soil receiv- 
ing increasing applications of commercial fertilizers was accompanied by an 
increase in the total solids and ash of the sap and in the amount of the 
fertilizer taken up by the plant. 

Determinations of total acidity showed an increase in the total acidity 
of the sap of plants fed with ammonium sulfate, disodium phosphate and 
monocalcium phosphate, when phenolphthalein was used as the indica- 
tor. 

The relation between the increase in total acidity and in the phosphorus 
content of the sap when the plants were fed with disodium phosphate 
proved that the phosphorus was taken in the form of dihydrogen phos- 
phate, due, as was shown, not entirely at least to absorption of the base 
by the soil but to the selective action of the plant. Applications of potas- 
sium sulfate had no effect upon the acidity of the sap. 

The sap from the stems of plants grown on soil to which large applica- 
tions of potassium sulfate had been made showed a higher total sugar 
content, the same results being obtained with extracts of foliage. The 
starch content of the foliage of such plants was lower. These data indi- 
cate a more rapid hydrolysis of the starch in the foliage in the presence of 
an excess of potassium sulfate. The increased exudation of nectar in the 
flowers of these plants probably resulted from this increase in sugar con- 
tent. 



23 

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Urbana, III. 



BIOGRAPHY. 
The author received his early training in the public schools of Paris, 
Illinois and in the high schools of Paris and Flora, Illinois and Terre 
Haute, Indiana. He received his Bachelor's degree in Chemistry from 
Wabash College in 1910 and has held the following positions since that 
time: 

1910-191 1, Instructor in Chemistry and Physics, Urbana, 111., High 

School. 
1911-1912, Assistant in Chemistry, Agricultural Experiment Station, 

University of Illinois. 
1912-1914, Assistant in Floriculture, University of Illinois. 
1914-1915, First Assistant in Floricultural Chemistry, University of 
Illinois. 
The author is a member of Sigma Xi, Phi Lambda Upsilon, Gamma 
Alpha, and the American Chemical Society. 



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